Add placeholders for the search lines

Summary:
Some people need them

BUG: 403445

Test Plan: Can be compiled, installed, can be spotted in the GUI.

Reviewers: #okular, ngraham

Reviewed By: ngraham

Subscribers: ngraham, #vdg, GB_2, okular-devel

Tags: #okular

Differential Revision: https://phabricator.kde.org/D18429

ui/bookmarklist.cpp

@@ -124,6 +124,7 @@ BookmarkList::BookmarkList( Okular::Document *document, QWidget *parent )
 
     m_searchLine = new KTreeWidgetSearchLine( this );
     mainlay->addWidget( m_searchLine );
+    m_searchLine->setPlaceholderText(i18n( "Search..." ));
 
     m_tree = new QTreeWidget( this );
     mainlay->addWidget( m_tree );

ui/searchwidget.cpp

@@ -37,6 +37,7 @@ SearchWidget::SearchWidget( QWidget * parent, Okular::Document * document )
     // 2. text line
     m_lineEdit = new SearchLineEdit( this, document );
     m_lineEdit->setClearButtonEnabled( true );
+    m_lineEdit->setPlaceholderText(i18n( "Search..." ));
     m_lineEdit->setToolTip(i18n( "Enter at least 3 letters to filter pages" ));
     m_lineEdit->setSearchCaseSensitivity( Qt::CaseInsensitive );
     m_lineEdit->setSearchMinimumLength( 3 );

ui/side_reviews.cpp

@@ -117,6 +117,7 @@ Reviews::Reviews( QWidget * parent, Okular::Document * document )
     m_view->setModel( m_authorProxy );
 
     m_searchLine = new KTreeViewSearchLine( this, m_view );
+    m_searchLine->setPlaceholderText(i18n( "Search..." ));
     m_searchLine->setCaseSensitivity( Okular::Settings::self()->reviewsSearchCaseSensitive() ? Qt::CaseSensitive : Qt::CaseInsensitive );
     m_searchLine->setRegularExpression( Okular::Settings::self()->reviewsSearchRegularExpression() );
     connect(m_searchLine, &KTreeViewSearchLine::searchOptionsChanged, this, &Reviews::saveSearchOptions);

ui/toc.cpp

@@ -17,6 +17,7 @@
 #include <QContextMenuEvent>
 
 #include <klineedit.h>
+#include <KLocalizedString>
 
 // local includes
 #include "ktreeviewsearchline.h"
@@ -34,6 +35,7 @@ TOC::TOC(QWidget *parent, Okular::Document *document) : QWidget(parent), m_docum
 
     m_searchLine = new KTreeViewSearchLine( this );
     mainlay->addWidget( m_searchLine );
+    m_searchLine->setPlaceholderText(i18n( "Search..." ));
     m_searchLine->setCaseSensitivity( Okular::Settings::self()->contentsSearchCaseSensitive() ? Qt::CaseSensitive : Qt::CaseInsensitive );
     m_searchLine->setRegularExpression( Okular::Settings::self()->contentsSearchRegularExpression() );
     connect(m_searchLine, &KTreeViewSearchLine::searchOptionsChanged, this, &TOC::saveSearchOptions);